Crimping tool for tube fittings



Nbv. 19, 1957 J. w. WINGATE 2,813,442 CRIMPINGQTOO'LT FOR TUBE FITTINGS Filed July 21, 1955 IN V EN TOR. Joseph lMl l z'lzja Ze Soho/mm M x 4 7 0ENEY5 Unite States Patent 2,813,442 CRIMPING TOOL FOR TUBE FITTINGS Joseph W. Wingate, Garfield Heights, ()hio ApplicationJuly 21, 1955, Serial No. 523,441

13 Claims. or. 81-15) The present invention relates to tools for crimping metal tube fittings to secure the fittings to flexible-tubing such as rubber and composition air hose and the like and to make a fluid-tight joint between the tubing and the fitting.

An object of the invention is to provide a sturdy, durable, adjustable Crimping tool which may be operated easily and manufactured inexpensively.

A further object of the invention. is to avoid kinking of the flexible hosing or other tubing to which the littingis attached without permitting the skirt of the fitting to flare.

Still another object of the invention is to locate the crimp formed in the fitting accurately with respect to the longitudinal dimensions of the fittings so that an adequate length of skirt will be formed while insuring that the tubing attached to the fitting is securely clamped and at a sufficient distance from the end thereof.

Other and further objects, features and advantages of the invention will become apparent as the description proceeds. i

In carrying out the invention in accordance with a preferred form thereof,a rectangular base-plateis employed of oblong shape, approximately twice as long as wide, with a central cutaway portion. Inwardly directed channels are formed along two sides of the front sur' face of the base-plate and a crosshead is provided with edges slidably fitting in the channels.

Crimping rollers are mounted at one end of thebaseplate. A crimping roller unit consisting of one or two crimping rollers is also mounted on the crosshead so that the tool may be rotated around the tube fitting and the crimping rollers may be forced into engagement with the lateral surface of the tube fitting by rotation ofan adjusting screw provided for adjusting the crosshead.

A better understanding of the invention will be afforded by the following detailed description considered in conjunction with the accompanying drawing, in which:

, Fig. 1 is a plan view of a crimping tool forming an embodiment of the invention. i1

Fig. 2 is a view of a longitudinal section represented as cut by a broken plane 22 indicated inFi'g. 1.

Fig. 3 is an end view of the apparatus of Figs, 1 and2 as seen from the end away from the adjustingh'andle.

Fig. 4 is a fragmentary enlarged view in longitudinal section of the apparatus showing a fitting which has been attached to the end of a length of tubing and showing a portion of one of the crimping rollers.

Fig. 5 is a fragmentary longitudinal sectional view of one of the crimping rollers.

Fig. 6 is a view of the' longitudinal section of a medi fied crimping roller arrangement.

Fig. 7 is a detail plan view of a swinging locating member, and 7 1 1 Fig. 8 is an elevation of the locating member.

Like reference characters are utilized throughout the drawings to designate like parts. v

2,813,442 Patented Nov. 19, 1957 'ice tangular or oblong base-plate 11 approximately twice as long as wide with a pair of crown, crimping rollers 12 and13rotatably secured to one end of the base-plate, and a slidable crosshead 14 which in turn carries a crimping roller unit consisting in the arrangement illustrated of a pair of crown, crimping rollers 15 and 16 rotatably mounted on the crosshead 14. It will be understood, however, that the invention is not limited thereto and if desired the crimping roller means carried by the crosshead 14 slidable on the base-plate 11 may consist of a single roller instead of two.

There is an adjusting screw 17 with a knurled knob or handle 18 for either backing off the crosshead 14 or moving it toward the end of the base-plate 11 carrying the crimping rollers 12 and 13 for forcing the rollers against the lateral surface of a threaded tube fitting 19 in order to crimp the fitting 19 around theend 21 ofa length of tubing 22 for securing the fitting 19 to .the tubing 22 and making a fluid-tight joint for enabling threaded connections to be made to flexible tubing or hose, carrying gases or liquids.

For rotatably securing the fixed crimping rollers 12 and 13 at the end of the base-plate 11, flat-head shoulder screws 23 are provided each having a head consist= ing of a cylindrical portion 24 and a flange or shoulder 25 with an eye or slot 26 for receiving a screw driver and a threaded shank .27 extending through one of two lathe form of crimping tool illustrated there is a recopenings 28 in the plate 11 and secured to theplate 11 by nuts 29. The rollers 12 and 13 each has a bore' 9 and a counter bore 10 of such size as to form a free running fit with the head portions 24 and 25 of one of the screws 23 so that the heads of the screws 23 serve as journals for the rollers 12 and 13. i It willbe observed that the central portion of the base-plate 11 is cut away to leave an elongated, substantially six-sided opening 31 for permitting tube fittings 19 and lengths of tubing or flexible hosing 22 to be passedthrough the opening31.

In order that the crosshead 14 may be accurately mounted on the plate 11 for longitudinal sliding movement thereon and without warping or twisting in angular relationship thereto, the base-plate 11 is formed with confronting channels 32 and 33 at the sides thereof ex tending along the front surface 34 of the base-plate 11. The channels 32 and 33 are formed by overhanging ledges 35. i

For slidable mounting in the channels 32 and 33, the crosshead 14 is formed as a plate 36 with edges 37 and 38 of such width and thickness as to form a sliding fit in the channels 32 and 33. Preferably a transversely extending bracket 39 is also formed on the plate 36 of the crosshead 14 for cooperation withend 41 of the adjusting screw 17. i p t For securing the crimping rollers 15 and 16 to the crosshead 14, shoulder screws 42 are provided somewhat similar to the screws 23 but having shallower cylindrical head portions 43. One or two openings 44 are provided in the crosshead plate 36, according to whether oneor two crimping rollers are used on thecrosshead, to receive the threaded shank 27 and to permit the screw 42 to be secured by the nut 29.

The adjusting screw 17 is mounted at the end of the base-plate 11 away from the rollers 12 and 13. For this purpose a suitable crossblock 45 may be formed in the base-plate 11, or as illustrated, preferablya separate crossblock is provided secured to the base-plate 11 by flathead screws 46. r

For enabling the adjusting screw 17 to back off the crosshead 14 a shoulder screw 47 is provided havinga flange or shoulder portion 48 and a neck'or journal portion 49 adapted to fit loosely in an opening 51 in the bracket 39 of the crosshead 14. The screw 47 has a threaded shank 52 threaded into a threaded axial socket 53 in the end 41 of the screw 17. Left-handed threads may be employed to avoid loosening the screw 47. The head or handle 18 is secured to the screw 17 in any desired manner as by means of a threaded s'ocket 54 and a lock nut 55. 'It will. be observed that each of the crimping rollers 12 and 13, which are mounted on the base-platel-l, and therefore may be, referred to as stationary crimping .rolle'rs, 'is a crown roller having a crown or bulgingportion 56 between'two cylindrical portions-57 and 58, the latter of -slightly greater diameter, say about .005 to about .015? greater diameter, preferably :of the order'of about .010" greater diameter than the former. The cylindrical portion 57 toward and seated-with itsend face 60 against the'front surface '34. of the :plate ll servesas a neck or collar forconfiningtlie skirt of the-fittingduring crimping. In the arrangement illustrated, the neck 57rhas somewhat greater axial length than-thecylindrical portion-58.

The'cf'owned crimping rollermeans 1 5, 16,-on'the crosshead .14, :which move laterally with; the crosshead '14 :and may therefore. be referred to as Inova'ble crimping roller means, also comprise er'ow'n roliersfe'ach with aicrown or bulging portio'rr59 correspondingin shapeand-tsize toath'e crowns 56 of the rollers 12 and :13,"and-Zlj'CYiihdIiGflljPOF Lion. ;61 "corresponding in length and diameter to, the cylindricalrportion 58 ofthe stationary crimping rollers 12 an'dr13. However; not portion cdrresponding'ttothe cylindrical-portion 57 of the crimping rollers 12 ,andL-13 tis neededfand, end,- faces -67.i-of the 'crossheadarollers 15 and --16::se'at against front' surface 68 ofthecr'osshead. The

plate-portion 36 'of1the crossheadl4serves as aspace'r and provides the requisite axialgdisplacement'of the-crowns 59jofthe-n1ovable rollers-12 and-"13 'so' that thecrimping 'roller crowns 56-and 59-:arethe'same 'distance from the front surface 34 of the base-plate 1*1' and are symmetric with respect to acommon plane of rotation which is also the, rotational plane of the fixed rollers 12, "13.

Therelationship between-the diameters of the'roller portions56- and 58;and likewise the roller porti6ns=59t and 6 1 issuch that the fitting 19 will'be crimped to the desired extent with the cylindrical portions 58 and"61=:of the :crimping v rollers bearing "against the external later-absurface'62- f'the tubular -fitting 19. However, those-dimensions of the rollerswhich-aretoward the surface 34 f the base-plate 11 from the plane-"of --the'crests of the roller crowns areprefera'blyrelieved in order'tozavoid k k ng,- eutting,;notching or otherwise "weakeningathe portion-of the surface of the flexible hose or other tubing 1 '22 where the end 63 of the skirt 64 of the fitting 19 bears against the; tubing 22. 1 Nevertheless the cylindrical collar or neck57'is provided on'eachof the fixed 1'o'llers'1 22and 13'and the relationshipbetween' the dimensions of r the various .portions ao .z he crimping rollers are T such as to avoid fiaring of the skirti-6 4- of the'fitting 19.

,, Preferably the diameter of the flare preventing-neck 57 of the rollers 12 and 13 is less than the fdiameter of the cylindrical portions 58* and ;61 of the"rolle'rs;12, 13,15 and 1 6 Moreover, the radius off thet 'part' 6540f, the crownj56 (9r59 'ofthe crimping rollers 12, 13 (15and 16) asidentified for sake of illustrationin Fig. 5, which crown partis; toward the baseplate 11 and, therefore, to- .ward the open end of the skirt 64 of the fitting,:-is -relieved with respect to the radius of other-part 66- of 'the crown 56 (or 59). The radii ofthe longitudinal section as illustrated in Figs.-2;and may be made diiferent in the curves definirig the crown parts 165 and 66. For exarnplethe radius of the 'crownpart 65 ispreferably. greater than the radiusof the crown, part '66. The surface curvaturesof the crowns 56. and 59 of the .crirnping'rollers 12, 13, and 16, independently of thediiferent di-ameters of the cylindrical portions 57, 58 and61- of these rollers, providecertain reliefs} which tend-to :avoidkinking 'of tubing by the end-'63 of'the skirt 64 of=the fitting 19 ar1d promoteayoidanceofiflare of -theskirt' 64. v V

The distance betweenlower edge .71 ofzthe erosshead 14 and the axis of the threaded screw shank 27 is preferably less than the radius of the cylindrical necks 57 of the stationary crimping rollers 12 and 13 in order that the principal radial pressure contact between the skirt 64 and the parts of the crimping tool will be with the neck portions 57 of the crimping rollers 12 and 13, thus avoiding frictional engagement between the skirt 64 and the edge 71 of the crosshead 14. However, the edge 71 of the crosshead 14 may be employed if desired for confining the .skirt 64 of the fitting 19 r In utilizing the crimping "tool, the tubing 22 is first inserted into the fitting 319., preferably bringing the parts into the opening .31 in the base plate 11 and the end 63 of the skirt 64 is'broughtflush with the front face 34 of the plate 11 in order that a crimp 72 will be formed in the fitting 19 at a desired uniform distance from the end 63 of the skirt 64. For accomplishing such uniform location, locating stop members .73 .and 74 are provided which are pivotallymounte'd atithesame endofthe "baseplate 11 as the stationary crimping rollers '12 and 13 at the corners of the .base-iplate 11 as illustrated in Fig. 1.

The locating stop members 73 and 74 are in the form of anglemembers each having an arm v75 (Fig.7) with a hole 76 thereintdreeeive'apivotsinthe form'of a shoulder head mounting screw '77t-threaded in the base-plate 11. There is a second 'arm l7:8.1formed with a transversely extending block portion79 :adapted to extend transversely into 'the icutaway' portion LOT" opening :31. in the base-block 11. It will be observed that the angle members or'arms '7-3 and 74 slide along-backrsur'face 7010f the base-plate =11as theypivot-around thexpivotl screws '77 while the block portions 79wextendstoward-th'e front surface 340i the, base-platen and=are1of isuch dimensions ,that their facess80 lie in theisamefplaneiaslthe front surface 34 of the base-plate-l'l.

Preparatory tocrirnping a: fitting and'uniting it with a length; of tube 22, the fittin'g,19 is secu'red Eat .a suitable location as on a bench by means of a vise or preferably by using "a jig. mounted in an opening iril the'top 'of the bench adapted to receive a hexagonalnut iportion 81 of the fitting-19-loosely to:.prev'en1: itsfrotati'on. 1'With"the:crjosshead 1'.4 of the tool backed ofinbyi'reverseirotation of-' the handle =18,@.the"tool: is cthen placed around the fitting 1 9 they skirt. of the fitting-z 19.

The mmvable crimping rollers 15 -and '16 "are 'then .brought iinto; position by; advancingithe crosshead' 14 by means of the adjustingzscrewhandlei18. The end ofthe length of hofseor. other tnbing. 22 1is then rinserte'd inthe fitting 19 around its; central. core 83. The. tool 'is'jthereafter rotated around the axisof'thexfitting 19 while-progres sively drawing in the-movable crimpingirollers 15 and 16 by further rotation ofvthechandle-lflof the adjusting screw 17 around the: axisvof; thesadju'stingi'screw 17, while also revolvingv thetool bodily'lbyizmeans 10f its handle"18 around the axis ofz-thevfittingc19. When the fitting- 19 has been fully crimped zbygproducing: the conformation illustrated in Fig.4, the orosshead 14 is backed off by reversing therotationr ofrtheiahandle.18 and the 'locating'arms 73 and 74 areswungroutwardvsozas toblear the tubing 22 and the fitting 19*Whereuponthe:tubing 22 and the 'fitting 19, whichz has-{beenattachedtd. itmay be lifted out from the bench-andwthe "jig holdingthe nut portion 81' of the-fitting- 19, :after which the s'ameE'procedure may be repeated with another fittingandxlength of tubing.

The crimping rollers 12,-: 13,":15'and 16 areso mounted that the bulging portions' or crowns 56z and 59 are all the same distaficei frdrri the surface '34 of the base-plate 11 and means'are provided for retaining the skirt 64 of the fitting 19 without flaring. However, the invention is not limited to the specific structure described nor to the neck or collar 57 being integral with the crown 56. For example, as illustrated in Fig. 6, a separate crown roller 84 and collar 85 may be provided, both rotatable upon the head of the shoulder screw 23. In this manner thestationary crown rollers 84 and the movable crown rollers 42 are identical and the stocking of parts for replacement is simplified.

The ledges 35 overhanging the channels 32 and 33 ex tend further in the direction perpendicular to the surface 34 of the base-plate 11 than the middle of any of the crowns 56 or 59 of the crown crimping rollersso that rigid support of the crimping rollers is provided, assuring constancy of the spacing of the crimp 72 from the end of each fitting and assuring that the axes of the crimping rollers will remain parallel to each other and perpendicular to the base-plate 11. 3

In accordance with the patent statutes the principles of the present invention may be utilized in various ways, numerous modifications and alterations being contemplated, substitution of parts and changes in construction being resorted to as desired, it being understood that the embodiments shown in the drawings and described above are given merely for purposes of explanation and illustration without intending to limit the scope of the claims to the specific details disclosed. i

What I claim and desire to secure by Letters Patent of the United States is: t

l. A crimping tool for tube fittings comprising in combination a substantially rectangular base plate having a central cut away portion providing a through opening for receiving a tube fitting, the base plate having first and second ends each spaced from the cut away portion, front and back surfaces, and inwardly directed channels along two sides of the base plate on the front surface, a crosshead having edges slidably fitting in said channels, crimping roller means mounted on the crosshead symmetrical with respect to the crosshead and the base plate, crimping roller means mounted on the base plate at the first end symmetrical with respect to the base plate, whereby the roller means mounted on the base plate and the roller means mounted on the crosshead are symmetrical with respect to each other, one of said base plate and crosshead crimping roller means comprising circular toroidally curved crown means and a coaxial cylindrical means for confining the skirt of a received tube fitting during a crimping operation, the circular crown having an axial length greater than its radial extent outwardly of the cylindrical surface generated by the cylindrical skirt confining means, a block at the second end of the base plate, said block having a threaded opening therein the axis of which is longitudinal with respect to the base plate, an adjusting screw threaded through the block opening and atone end rotatably secured to the crosshead, whereby the crimping roller means carried by the crosshead may be forced relatively toward the crimping roller means carried by the base plate to clamp therebetween a tube fitting received in the through opening of the base plate and whereby the crosshead crimping roller means may be backed off after crimping such tube fitting, the symmetrically mounted roller means on the base plate coacting with the symmetrically mounted roller means on the crosshead to locate the received tube fitting in predetermined position centrally in the base plate opening and clear of the walls of such opening and to retain such fitting in such central position as the tool is relatively rotated about the fitting in a crimping operation, and the cylindrical skirt confining means being held against the skirt of a crimped tube fitting during such relative rotation of the crimping roller means of the crosshead and of the base plate about the tube fitting whereby to prevent flaring of such skirt.

l 2. A crimping tool as in claim 1 wherein the crimping roller means carried by the crosshead comprises a first pair of crimping rollers and the crimping roller means on the base plate comprises a second pair of crimping rollers.

3. A crimping tool as in claim 1 wherein the crimping roller means on the base-plate has a substantially cylin- 4. A crimping tool for tube fittings, as in claim 1,-

wherein the crimping roller means on the base-plate has first and second cylindrical portions and a bulging crown portion of greater radius in between the cylindrical portions, serving to crimp the fitting, the first cylindrical portion toward the base-plate serving to confine the skirt at the end of the fitting and the second cylindrical portion serving to fit against the uncrimped portion of the fitting adjacent to the crimped portion on the opposite side from the skirt, and the crimping roller means on the crosshead has a bulging crown portion corresponding to the crown portion of the crimping roller means on the base-plate, and a cylindrical portion corresponding to the second cylindrical portion of the roller means on the base-plate.

5. A crimping tool as in claim 4 wherein the radius of the second cylindrical portion of the crimping roller means on the base-plate exceeds the radius of the first cylindrical portion for confining the fitting skirt, whereby the skirt of the fitting is effectively confined without flaring thereof or kinking of tubing in the fitting, the crimping roller means on the crosshead having a bulging crown portion conforming in shape and dimension to the bulging crown portion of the crimping roller means on the baseplate.

6. Apparatus as in claim 5 wherein the radius of the bulging crown portions of the crimping roller means are relieved toward the base-plate and the crosshead for promoting avoidance of flare of the skirt of the fitting being crimped.

7. A crimping tool for tube fittings comprising in combination a base-plate, first crimping roller means symmetrically mounted on the base-plate with axes perpendicular to the plane of the base-plate, a crosshead slidable on the base-plate and carrying second crimping roller means adapted to cooperate with the first crimping roller means, means for adjusting the position of the crosshead, swinging stop members adapted to be brought into position between the first crimping roller means and the crosshead crimping roller means for locating a tube fitting and adapted to be swung away from said position for releasing a tube fitting, said crimping roller means having bulging crown portions with peripheries adapted to contact the periphery of a tube fitting to be crimped for producing a crimp therein with the radius of the bulging crown portion being greater at one end than at the other end, one of said crimping roller means being provided with means adjacent the small radius portion of the crown thereof for confining the skirt of the tube fitting to be crimped and avoiding flare thereof.

8. A crimping tool for tube fittings comprising in combination a base-plate, first crimping roller means symmetrically mounted on the base-plate with :axes perpendicular to the plane of the base-plate, a crosshead slidable on the base-plate and carrying second crimping roller means adapted to cooperate with the first crimping roller means, said crimping roller means having bulging crown portions with peripheries adapted to contact the periphery of a tube fitting to be crimped for producing a crimp therein with the radius of the bulging crown portion of the crimping roller means being greater at one end than at the other end, one of said crimping roller means comprising a pair of crimping rollers and one of the crimping roller means being provided with means adjacent the crown portion for confining the skirt of the tube fittingto be crimped and avoiding flare thereof.

9. A crimping tool for tube fittings comprising in combination a base-plate having a central cutaway portion, first and second ends beyond the cutaway portion, front and back surfaces, and inwardly directed channels along two sides of the base-plate on the front surface, a crosshead having edges slidablyfitting in said channels, a pair of crimping rollers rotatably mounted on said base-plate at the first end thereof, crimping roller means. rotatably mounted on said crosshead, said crimping rollers, and.

crimping roller means including crowns, a crossblock at the second end of said base-plat,c,, said crossblock having a threaded opening therein with an axis longitudinal with.

respect to said base-plate, an adjusting screw threaded into said threaded opening, rotatabl'y secured to said crosshead whereby, when the tool is rotated around a tube fitting, the crimping roller means carried by the crosshead may be forced toward the said pair of crimping rollers on the base-plate and against the tube fittingto be crimped, and, may be backed off when the crimping has been accomplished, said inwardly directed channels being formed by overhanging ledge portions extending from the front surface of the base-plate in a direction perpendicular thereto further than the distance from the front surface of the base-plate to the middle of the said crowns of the crimping rollers.

10. A crimping tool for tube fittings comprising in combination a base plate having a central through opening to receive a tube fitting to be crimped, said base plate having means defining a pair of spaced parallel channels disposed on opposite sides of the through opening in confronting relation to one another, crimping roller means rotatably mounted on the base plate intermediate the channels in overhanging relation to the through opening, a crosshead carried by the base plate and guided in the channels for rectilinear sliding movement across the through opening toward and away from the crimping roller means, crimping roller means rotatably mounted on the crosshead and overhanging the crosshead and the through opening for engaging a tube fitting disposed in such opening, the roller means on the base plate comprising a circular radially projecting crown, the roller means on the crosshead also comprising a circular radially projecting crown, the radial crowns of the base plate and crosshead roller means being disposed in a common plane, one of said roller means also comprising a substantially cylindrical element coaxial to and of less diameter than the circular crown of the corresponding roller means, said cylindrical element being engageable. with the skirt of a tube, fitting being crimped between the roller means of the base, plate and of the crosshead in a normal crimping operation to confine such skirt and prevent flaring thereof during the crimping operation, operating means connecting the. crosshead to the base plate, said operating means being actuatable in one direction for advancing the crosshead toward the crimping roller means on the base. plate for clamping between the base plate crimping roller means, and the crosshead crimping roller means a tube fitting; disposed in the through opening, and said operating means being actuatable in a reverse direction to withdraw the crosshead in releasing a crimped tube fitting.

11. A crimping tool for tube fittings comprising in combination a base plate having a, central through opening to receive a tube fitting to be crimped, said, base plate having means defining a pair of, spaced parallel channels disposed on opposite sides of the through opening in confronting relation to onev another, the through opening being located wholly within the limits established by the ends of the channels, crimping roller means rotatably mounted on the base plate intermediate, the channels in overhanging relation to the through opening, a. Cross head carried by the base plate and guided in the chanall) nels for rectilinear sliding movement across, the through. opening toward and away from the crimping roller means, crimping roller means rotatably mounted on the crosshead and overhanging the crosshead and the through opening for engaging a 'tube fitting disposed in such opening, the roller means on the base plate comprising a: circular radially projecting; crown, the roller means on the. crosshead also comprising a circular radially projecting crown, the radial crowns of the base plate and crosshead roller means being disposed in a common. plane, one of said roller means also comprising a substantially cylindrical element coaxial to and of less diameter than the circular crown of the corresponding roller means, saidcylindrical element being engageable, with the skirt of a tube fitting being crimpedbetween the roller means of the base plate and of the crosshead in a normal crimp ing operation to confine such skirt and prevent flaring thereof during the crimping operation, operating means, connecting the crosshead to the base plate, said operating' means being actuatable in one direction for advancing the crosshead toward the crimping roller means on the base plate for clamping between the base plate crimping roller means and the crosshead crimping roll'en means a tube fitting disposed in the through opening, and said operating means being actuatable in a reverse direction to withdraw the crosshead in releasing a, cri'mped tube fitting.

12. Ina tool for crimping a tube fitting having a thin walled substantially cylindrical skirt, the. tool being of the type in which the tube fitting is clamped between crowned roller means and relatively rotated so that the fitting skirt is progressively deformed radially inwardly in the formation of an annular groove about the skirt to grip an internal tube, the improvement which comprises a crimping roll'erhaving a circular toroidally curved crown anda pair of, substantially cylindrical control sections dis-. posed one on each; side of and contiguousv to the crown, said control sections being coaxial to one another and to the crown and being, of less diameter than the crown, the crown being relatively shallow radially and having an axial length between the cylindrical, sections about twice its. radial height as measured outwardly of the cylindrical surface generated by either control section, whereby in a normal crimping operation the crown of the roller is received to its full effective radial depth in said groove in the. skirt of the tube fitting and the portions of the skirt on each side of such groove are confined by the cylindrical control sections of the roller, and one of said cylindrical control sections being of slightly greater curvature radius than the other whereby to effect a relatively tighter grip on the cylindrical skirt of a tube fitting being crimped.

13. In a tool for crimping a tube. fitting having a thin walled substantially cylindrical skirt, the tool being of the type in which the tube fitting clamped between crowned roller means and relatively rotated so that the, fitting skirt is progressively deformed radially inwardly in the formation of an annular groove about the skirt to grip an internal tube, the improvement which comprises a crimping roller having a circular toroidally curved crown and a pair ofsnbstantially cylindrical control sections dis-. posed one. on each side of and contiguous to the. crown, said control sections being coaxial to one another and to the crown and being of less diameter than the, crown, the crown being relatively shallow radially and having an axial. length between the cylindrical sections about twice its radial height as measured outwardly of the. cylindrical surface generated by either control section, whereby in a normal crimping operation the crown of the roller, is received to. its full effective radial depth in said groove in the skirt of the tube fitting and the portions of the skirt on each side of such groove are confined by the cylindrical control sections of the; roller, one. of said cy indrical. control sections being, of; greater axial. length than the other, and one of said cylindrical control sec- 9 10 tions being of slightly greater curvature radius than the 1,809,126 Johnson June 9, 1931 other whereby to efiect a relatively tighter grip on the 1,880,246 Greiner Oct. 4, 1932 cylindrical skirt of a tube fitting being crimped. 2,095,310 Brandt *Oct. 12, 1937 2,197,099 Dewar Apr. 16, 1940 References Cited in the file of this patent 5 2,337,362 Willinger Dec. 21, 1943 UNITED STATES PATENTS FOREIGN PATENTS 3 1 th O t- 19, 1926 02 Au tralia Jan. 26, 1926 1,619,064 Ferguson 1, 1927 722,278 Great Britain Jan. 19, 1955 1,753,963 Mauser Apr. 8, 1930 

